(NASHVILLE, Tenn.) — A 65-year-old man is accused of killing his wife and grandson at his home in Nashville, before killing himself, while his 4-year-old granddaughter was able to escape the carnage and survive, police said.

Terry Majors, 65, is believed to have shot and killed his wife, Leigh Shea-Majors, 61, and his 6-year-old grandson, Ty Dodson, in an apparent double murder-suicide around 7:30 p.m. Saturday, according to the Metropolitan Nashville Police Department.

The 4-year-old ran to a neighbor for help and was unhurt, said police.

In a Facebook post from the boy’s uncle, Chase Dodson, Dodson said Ty, who had turned six less than two weeks earlier, was visiting his maternal grandparents Saturday when the “visit went extremely wrong.”

Ty “was constantly smiling and wanting to take care of everyone,” his former preschool teacher, Tabitha Collins, told ABC Nashville affiliate WKRN. “He has a little sister that’s in preschool this year, who he walks in and just makes sure that she would get to school and in the classroom okay.”

“When those kids come into your classroom, they become your own and I can’t describe how much I love Ty,” Collins said.

“Why?” she asked. “He’s so young.”

The motive is undetermined and the investigation is ongoing, police said Wednesday.